Combination High-Dose Cyclophosphamide and Bortezomib Is Safe and Effective for Stem Cell Harvesting in Chemotherapy Refractory Multiple Myeloma.
Bibliographic record
Abstract
Abstract Introduction: High-dose melphalan and autologous stem cell transplantation is the accepted therapy for most patients with multiple myeloma (MM) following steroid-based induction therapy. In a significant proportion of patients, however, the disease is refractory to standard induction. The use of dose-intense combination chemotherapy, such as D-PACE (dexamethasone, doxorubicin, cyclophosphamide, and cisplatin), may affect the ability to harvest an adequate number of hematopoeitic stem cells prior to transplantation. In addition, in those patients not achieving adequate cytoreduction despite combination chemotherapy, there is a theoretical risk of stem cell product contamination by malignant plasma cells. Bortezomib is a therapeutic agent with a novel mechanism of action, which in preliminary studies appears to be synergistic to alkylating agents and does not appear to affect stem cell yield. We piloted the addition of bortezomib to high-dose cyclophosphamide during stem cell harvesting in a series of patients failing to achieve an adequate response to D-PACE salvage. Patients and Methods: Between 2002 and 2006, fifteen MM patients refractory to standard dexamethasone-based induction therapy received ≥ 2 cycles of D-PACE prior to proceeding to autologous stem cell harvest and transplantation. 7/15 patients achieved adequate cytoreduction and proceeded to high-dose cyclophosphamide (3 g/m2) and filgrastim plus ancestim stimulation for stem cell mobilization. However, 8 patients in this cohort did not achieve adequate disease cytoreduction following D-PACE. Therefore, bortezomib was added to the mobilization regimen on days 1, 4, 8, and 11, in addition to high-dose cyclophosphamide given on day 11. Identical growth factor stimulation was provided. Response assessment included days to stem cell harvest, number of CD34 cells harvested, plasma cells in the product, disease response, and hematologic parameters. Results: Pre-treatment toxicities from D-PACE were similar in both groups. The addition of bortezomib to cyclophosphamide during stem cell mobilization did not lead to increased symptomatic toxicity. Grade 3/4 thrombocytopenia occurred in 5/8 patients receiving combination bortezomib/cyclophosphamide. No episodes of significant bleeding, peripheral neuropathy, or skin rash were noted. The average CD34-positive stem cell harvest in both groups was >5.0 × 106/kg. Time to stem cell harvesting was not significantly different between the groups. Flow cytometric examination of the harvested product from the bortezomib/cyclophosphamide group consistently demonstrated <2% cells bearing plasma cell markers. One patient in each group failed to mobilize sufficient stem cells. Bone marrow plasmacyte counts following combination therapy and harvesting decreased in all assessed patients. Time to engraftment was similar in both groups. Post-transplant disease control and survival remains to be assessed, as some patients in the combination group have only recently undergone transplantation. Conclusion: The addition of bortezomib to high-dose cyclophosphamide during stem cell mobilization does not increase toxicity or decrease stem cell harvest yield or quality, and appears to achieve adequate disease reduction in patients otherwise refractory to combination chemotherapy. This may result in improved relapse-free survival in patients with refractory MM.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".